Myofibroblasts in filtration operations.

Myofibroblast cells, involved with collagen production, bridge incisional sites after two filtration operations. These spindle-shaped cells appeared as early as the seventh postoperative day and progressively developed through day 14. Later reparative stages were characterized by collagen production, though myofibroblast were strikingly absent after day 14. These histopathologic data obtained from healthy cats suggest that contraction of wound sites in early post-operative period may be causative in cicatrization failures of standard filtration procedures.